You wouldnt want your myostatin gene turnedoff.. the complete deregulation of protein synthesis would rapidly kill you.
Youd have to eat 10 or 15k calories a day just to survive.. all of your organs would be starved for protein.. nitrogen buildup would become unbearable on your tissues.. from the excessive recycling if muscle tissue.
Your muscles would rapidly develop and the rest of your body would starve todeathh.. probabyl a painful way to die. Mass organ failure.